SPECIFICATIONS FOE EAILBOAB CONCRETE WOBK. 341
possible the handling or turning over the same by means of shovels within the excavation or mold. Where it is not practicable entirely to complete one layer before commencing a second one, a plank, six inches wide or more, shall be securely fastened into the excavation or mold, against which the end of the layer of concrete shall be rammed, thus providing for a vertical joint in this layer of concrete, and if a second layer has to be stopped short of the full length of the work, a second cross plank, placed at least one foot back from the end of the first layer, shall be secured to the excavation or to the mold, against which to rara the second layer of concrete. Layers of concrete masonry must not be tapered off in wedge-shaped slopes, but must be built with square ends in the method above described, and the surface of each projection shall be finished hard and smooth, and flushed full of mortar, no porosities or loose stone being left thereon. Layers must not be made of greater thickness than six inches, unless specially permitted, and each layer must he thoroughly rammed, and the concrete must be of such consistency that heavy ramming will produce a slight quaking action. In other words, the concrete must be so thoroughly comparted that there will be no [Hires or open spaces between the stone of which it consists, which arc1 not thoroughly filled with mortar.
The inspector sha.ll insist upon tin* thorough compacting and ramming of all concrete*, and shall set* that a sufficient number of men, furnished with suitable rammers, an* assigned to this work. Rnough men shall be employed ramming, so that each batch may be spread and rammed before another batch is dumped within the mold. The ramming must IK* completed as the work progresses.
21. Foundation concrete*, if put into excavations which are not protected bv molds, need not have* nnv special attention given to the* finish of the concrete* against the* earth around it. Where it is necessary to use* molds in tlic construction of foundation work, the finer material of the concrete shall be worked to the outer portion of the mass against the molds, so as to insure the filling with mortar of all pores or open spaces between the concrete stone. As before described, the top stir-face of all foundation concrete shall be finished, so that no loose stone or open and porous places are left upon the* same, especially in the portions of the* foundation which project outside the upper portion of the work. If necessarv, the Inspector shall have the contractor make hatches of mortar, consisting of one part of cement to three parts of sand, the same being thoroughly mixed, and shall cover the whole surface* of the foundation concrete with enough of this mortar to flush full all such open, porous places.